Indent supports boolean attribute

Author: othree

indent/html.vim

@@ -921,6 +921,9 @@ func! s:InsideTag(foundHtmlString)
     else
       let idx = match(text, '\s\zs[_a-zA-Z0-9-]\+="')
     endif
+    if idx == -1
+      let idx = match(text, '<\w\+\(-\w\+\)*\s\zs\w')
+    endif
     if idx == -1
       let idx = match(text, '<\w\+\(-\w\+\)*')
       if idx >= 0